A conventionally-known contents reproducing devices is adapted to perform an intermittent reproduction control by storing reproduction data in a storing unit (see, for example, patent document 1).
FIGS. 10(a), 10(b) and 11(a) are block diagrams each showing a conventional contents reproducing device mentioned in the patent document 1. FIG. 11(b) refers to FIG. 1 in the patent document 1.
FIGS. 12(a) and 12(b) are flow charts showing an operation of the conventional contents reproducing device mentioned in the patent document 1. The operations of the conventional contents reproducing device shown in FIGS. 10(a), 10(b) and 11(a) will be described hereinafter.
FIG. 12(a) is a flow chart showing a contents reproducing operation of an input operation unit 1100 and a system control unit 2200 comprising a system state managing unit 1210, a system information storing unit 1220, and a contents reproduction control unit (B) 2230. A user request is inputted from the input operation unit 1100 (in step S1001). The system state managing unit 1210 reads current state information and system state transition information from the system information storing unit 1220. The system state managing unit 1210 makes the system state be transferred from the current state (referred to as “n−1”) to the next state (referred to as “n”) according to the user request (in step S1002). The contents reproduction control unit (B) 2230 controls the contents reproducing unit 1300 to perform a process (in step such as fast-forwarding) that is necessary at the next state (in step S1003).
FIG. 12(b) is a flow chart showing an operation of the contents reproducing unit 1300 including a reproduction data generating unit 1310, a contents storing unit 1330 and a reproduction data storing unit 1340, in other words, contents reproduction control unit (B) 2230 controls them. The reproduction data generating unit 1310 that received an instruction (a reproduction instruction for example) from the contents reproduction control unit (B) 2230 reads a content out from the contents storing unit 1330 and generates a reproduction data (in step S1102). The contents reproduction control unit (B) 2230 stores reproduction data generated by the contents storing unit 1330 into the reproduction data storing unit 1340 (in step S1103). The contents reproduction control unit (B) 2230 determines the amount of available memory space in the reproduction data storing unit 1340 according to a threshold α. Then, if the amount of available memory space is higher than the threshold α(determination result=NO), the process is sent back to S1102 (in step S1104). If the amount of available memory space of the reproduction data storing unit 1340 is below the threshold α(determination result=YES), the contents reproduction control unit (B) 2230 waits until the amount of available memory space in the reproduction data storing unit 1340 exceeds a threshold β (in step S1105). Though not mentioned in FIGS. 12(a) or 12(b), a reproduction data processing unit 1320 continuously performs a reproduction by constantly reading reproduction data from the reproduction data storing unit 1340.
FIG. 13 is a timing chart showing a change in the amount of reproduction data in the reproduction data storing unit 1340 of the conventional contents reproducing device, mentioned in the patent document 1, and controlled on the basis of the flow chart of FIG. 12. In particular, the vertical labels α and β on the vertical axis indicate amount data stored in the reproduction data storing unit 1340 when the amount of space available in the reproduction data storing unit 1340 reaches the thresholds α and β respectively.
FIG. 13 is a timing chart showing a change in the amount of reproduction data in the reproduction data storing unit 1340. The determination is made in determination step S1104 of FIG. 12 on whether or not the amount of reproduction data exceeds a vertical label α. On the other hand, the determination is made in determination step S1105 of FIG. 12 on whether or not the amount of reproduction data does not exceed a vertical label β.
The conventional contents reproducing device disclosed in the patent document 1 operates the reproduction generation unit 1310 at a faster pace than the reproduction data processing unit 1320, and stores reproduction data in the reproduction data storing unit 1340 prior to the reproduction by the reproduction data processing unit 1320. These operations enable the reproduction data generating unit 1310 to become inactive even during the operation of the reproduction data processing unit 1320. Moreover, the conventional contents reproducing device mentioned in the patent document 2 reduces energy consumption during its inactive stage by shutting the power supplied to the reproduction data generating unit 1310.    Patent document 1: Japanese Patent Laid-Open Publication No. H03-40269    Patent document 2: Japanese Patent Laid-Open Publication No. H07-161043